1. Field of the Invention
The invention is generally related to high performance polymeric materials and, more particularly, to phosphorus containing poly(arylene ether)s.
2. Description of the Prior Art
High performance engineering thermoplastics have become increasingly important in applications traditionally filled by metallic materials. Their use in the field of high strength, lightweight, composite resins has already found many applications in the aerospace, automotive, electronic and related industries. These industrially important thermoplastics include polyesters, polyamides, polyimides and poly(arylene ether)s (PAEs), such as the poly(arylene ether ketone)s (PEKs) and poly(arylene ether sulfone)s (PESs). The high glass transition temperatures (T.sub.g s) and/or melting temperatures (T.sub.m s) of these thermoplastics makes them ideal materials for use in environments where a part is exposed to high temperatures for prolonged periods of time. However, it has been found that these polymers become seriously degraded when exposed to atomic oxygen (AO), and this profoundly affects their utility in many aerospace applications as well as other applications where the part will be subjected to oxygen plasma etching. In particular, space shuttle missions which have employed such polymers have demonstrated considerable etching of the polymers due to atomic oxygen exposure while in low earth orbit upon return to earth; thereby severely reducing the useful lifetimes of the parts employing these thermoplastics. Hence, there is a need to identify materials which have an improved ability to withstand etching resulting from AO exposure.
Nonlinear optical (NLO) applications involve the interactions of electromagnetic fields in various media to produce new fields altered in phase, frequency, amplitude, or other propagation characteristics from the incident fields. Interest in materials suitable for NLO applications has increased tremendously in recent years due to data transmission needs of the computer age as well as the high-bandwidth optical switching needed in the telecommunications industry. In addition, sophisticated laser tools are in constant demand which has necessitated research directed toward finding new methods that enable individual laser pulses to perform specific functions or be readily detected in complex environments. To date, relatively few materials are known which are optically clear and which exhibit excellent hydrolytic and thermal stability as well as good electrical, mechanical and fire resistant properties.
Poly(arylene ether phosphine oxide)s (PEPOs) represent a relatively new class of engineering thermoplastics. These materials may be synthesized by the reaction of bis(4-fluorophenyl)phenyl phosphine oxide (BFPPO) or bis(4-fluorophenyl) methyl phosphine oxide (BFMPO) with bisphenols in various aprotic dipolar solvents utilizing sodium hydroxide or potassium carbonate as the base. This invention is particularly directed to the advantageous use of PEPO polymers and other polymers containing the phosphine oxide moiety in NLO applications or applications which&lt;xequire enhanced AO resistance, as well as to new and useful PEPO compounds.